* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
*
* For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU
+ * Documentation/RCU
*/
#include <linux/types.h>
#include <linux/kernel.h>
{
struct rcu_data *rdp = rsp->rda[smp_processor_id()];
struct rcu_node *rnp = rcu_get_root(rsp);
- struct rcu_node *rnp_cur;
- struct rcu_node *rnp_end;
if (!cpu_needs_another_gp(rsp, rdp)) {
spin_unlock_irqrestore(&rnp->lock, flags);
* one corresponding to this CPU, due to the fact that we have
* irqs disabled.
*/
- rnp_end = &rsp->node[NUM_RCU_NODES];
- for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) {
- spin_lock(&rnp_cur->lock); /* irqs already disabled. */
+ for (rnp = &rsp->node[0]; rnp < &rsp->node[NUM_RCU_NODES]; rnp++) {
+ spin_lock(&rnp->lock); /* irqs already disabled. */
rcu_preempt_check_blocked_tasks(rnp);
- rnp_cur->qsmask = rnp_cur->qsmaskinit;
+ rnp->qsmask = rnp->qsmaskinit;
rnp->gpnum = rsp->gpnum;
- spin_unlock(&rnp_cur->lock); /* irqs already disabled. */
+ spin_unlock(&rnp->lock); /* irqs already disabled. */
}
rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */
/*
* Record a quiescent state for the specified CPU, which must either be
- * the current CPU or an offline CPU. The lastcomp argument is used to
- * make sure we are still in the grace period of interest. We don't want
- * to end the current grace period based on quiescent states detected in
- * an earlier grace period!
+ * the current CPU. The lastcomp argument is used to make sure we are
+ * still in the grace period of interest. We don't want to end the current
+ * grace period based on quiescent states detected in an earlier grace
+ * period!
*/
static void
cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
* This GP can't end until cpu checks in, so all of our
* callbacks can be processed during the next GP.
*/
- rdp = rsp->rda[smp_processor_id()];
rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */
spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
- /* Being offline is a quiescent state, so go record it. */
- cpu_quiet(cpu, rsp, rdp, lastcomp);
-
/*
* Move callbacks from the outgoing CPU to the running CPU.
* Note that the outgoing CPU is now quiscent, so it is now
rnp = rnp->parent;
} while (rnp != NULL && !(rnp->qsmaskinit & mask));
- spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
-
- /*
- * A new grace period might start here. If so, we will be part of
- * it, and its gpnum will be greater than ours, so we will
- * participate. It is also possible for the gpnum to have been
- * incremented before this function was called, and the bitmasks
- * to not be filled out until now, in which case we will also
- * participate due to our gpnum being behind.
- */
-
- /* Since it is coming online, the CPU is in a quiescent state. */
- cpu_quiet(cpu, rsp, rdp, lastcomp);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&rsp->onofflock, flags);
}
static void __cpuinit rcu_online_cpu(int cpu)